1. Field of the Invention
The present invention relates to methods and organisms for concentrating and recovering metals and minerals from aqueous media.
2. Discussion of the Background
It is well-recognized that the oceans, lakes, and streams of the world contain significant quantities of metals, including rare, precious and strategic metals, e.g., gold. However, methods of economically extracting such metals are lacking.
The recovery of common minerals that are dissolved in seawater has been conducted for several centuries. It is economically feasible to extract materials contained at sufficiently high concentrations in seawater, such as salt, manganese and bromine. However, the more valuable minerals, e.g., gold, silver and platinum, exist in such small concentrations that extraction by current commercial means is more costly than can be justified by the value of the recovered metals.
In the last hundred years, many efforts have been made to develop efficient means of recovering these valuable metals from aqueous media. Such efforts have included chemical precipitation, resin gel filtration, etc. Many of these techniques were technically successful, but all were economically impractical since the cost of reagents, equipment, and energy exceeded the value of the recovered materials.
To be economically viable, the equipment for recovering metals and minerals from aqueous media must be extremely cheap to produce and maintain, and must be capable of processing relatively large volumes of water at a very low cost.
The present invention is directed to methods of economically extracting metals and minerals from an aqueous environment using aquatic organisms which are capable of removing metals and/or minerals from water and storing them in their tissues, i.e., concentrating metals and/or minerals, and then recovering the metals and/or minerals from the organisms.
Accordingly, it is an object of the present invention to provide methods of concentrating metals and minerals from aqueous media. It is another object of the present invention to provide aquatic organisms which are capable of concentrating metals and minerals from an aqueous medium.
The objects of the invention may be accomplished with a method of recovering metals and minerals from aqueous media by contacting an aqueous medium comprising at least one metal or mineral with a eucaryotic aquatic organism capable of concentrating the metal or mineral, to concentrate the metal or mineral in the organism; and then recovering the concentrated metal or mineral from the organism.
The objects of the invention may also be accomplished with a transgenic eucaryotic aquatic organism which is capable of concentrating at least one metal or mineral from an aqueous medium and expresses at least one heterologous gene which encodes a protein that effects the concentration of the metal or mineral in the organism.
The objects of the invention may also be accomplished with a transgenic eucaryotic aquatic organism which is capable of concentrating at least one metal or mineral from an aqueous medium, expresses at least one heterologous gene which encodes a protein that effects the concentration of the metal or mineral in the organism, and harbors a microorganism that is capable of concentrating the metal or mineral from an aqueous medium.
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description.